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991.
Hye Ree Yun Se-Hwan Joo Chan Ho Park Seong-Ki Kim Soo Chul Chang Soon Young Kim 《Journal of Plant Biology》2009,52(3):268-274
We examined the effects of brassinolide (BL) and/or an auxin (indole-3-acetic acid) on ethylene production and elongation
in the primary roots of maize (Zea mays). When these two hormones were applied exogenously, both increased ethylene production. Before the tenth hour after treatment
began, the influence of IAA was more evident than that of BL; the reverse was found beyond 10 h. When these hormones were
treated simultaneously, the increase in level of ethylene was greater than the sum of effects by each hormone. Such a positive
interaction was also recorded for changes in the activity of ACC synthase and the expression of its gene. For ACC oxidase,
however, the two hormones had no apparent influence. When applied separately, neither affected root elongation nor proton
extrusion. However, when given in combination, both phenomena occurred. Our results suggest that BL interacts with IAA to
promote ethylene biosynthesis and elongation in roots. Therefore, it is possible that brassinolide acts by inducing auxin,
which then stimulates both ethylene production (at the early stage) and root development. 相似文献
992.
Hye Jeong Park Jung-Moon Ko Nu-ri An Young Soo Kim Hyeon-Cheol Cha 《Journal of Plant Biology》2009,52(4):319-324
Concentrations of trans-resveratrol were analyzed in 36 Korean-grown grape cultivars, including cv. Kyoho. This cultivar has large irregular berries
and a deep-black skin and accounts for >15% of all grapevines grown in Korea. The content of trans-resveratrol is an important quality parameter, and its pattern of variability increased gradually until the time of harvest.
Its distribution also fluctuated significantly among leaves, seeds, and exocarps, with the highest amount (1,477 μg g−1 dry weight) occurring in the leaves. Among all cultivars evaluated here, trans-resveratrol contents were significantly higher
in “Cheongsoo” and “High Bailey,” their levels being 50% above the overall mean (i.e., 2.0-mg g−1 dry weight), whereas 14 cultivars had contents that were 10% less than that mean value 相似文献
993.
Sung Soo Whang 《Journal of Plant Biology》2009,52(4):312-318
Embryogenesis in transgenic Arabidopsis plants with GFP:mTn, a chimeric fusion of soluble shifted green fluorescent protein and a mouse actin binding domain, was
studied. Confocal laser scanning microscopy was used to determine patterns of formation and cellular responses during asymmetric
cell division. Before such cells divide, the nucleus moves to the position where new cell walls are to be formed. The apical–basal axis of the embryo develops mainly at the zygote to octant stage, and these events are associated with asymmetric divisions
of the zygote and hypophyseal cells. Formation of the radial axis is established from the dermatogen to the globular-stage
embryo via tangential cell division within the upper tiers. Bilateral symmetry of the embryo primarily happens at the triangular
stage through zig-zag cell divisions of initials of the cotyledonary primordia. All stages of embryogenesis are described
in detail here. 相似文献
994.
995.
Wha Ja Cho Jeong Min Shin Jong Soo Kim Man Ryul Lee Ki Sung Hong Jun-Ho Lee Kyoung Hwa Koo Jeong Woo Park Kye-Seong Kim 《Molecules and cells》2009,28(6):521-527
Previously, we have reported tissue- and stage-specific expression of miR-372 in human embryonic stem cells and so far, not
many reports speculate the function of this microRNA (miRNA). In this study, we screened various human cancer cell lines including
gastric cancer cell lines and found first time that miR-372 is expressed only in AGS human gastric adenocarcinoma cell line.
Inhibition of miR-372 using antisense miR-372 oligonucleotide (AS-miR-372) suppressed proliferation, arrested the cell cycle
at G2/M phase, and increased apoptosis of AGS cells. Furthermore, AS-miR-372 treatment increased expression of LATS2, while
over-expression of miR-372 decreased luciferase reporter activity driven by the 3′ untranslated region (3′ UTR) of LATS2 mRNA.
Over-expression of LATS2 induced changes in AGS cells similar to those in AGS cells treated with AS-miR-372. Taken together,
these findings demonstrate an oncogenic role for miR-372 in controlling cell growth, cell cycle, and apoptosis through down-regulation
of a tumor suppressor gene, LATS2. 相似文献
996.
Youn Wook Chung Daewon Jeong Ok Jeong Noh Yong Hwan Park Soo Im Kang Min Goo Lee Tae-Hoon Lee Moon Bin Yim Ick Young Kim 《Molecules and cells》2009,27(5):609-613
It has been reported that selenoprotein W (SelW) mRNA is highly expressed in the developing central nerve system of rats,
and its expression is maintained until the early postnatal stage. We here found that SelW protein significantly increased
in mouse brains of postnatal day 8 and 20 relative to embryonic day 15. This was accompanied by increased expression of SOD1
and SOD2. When the expression of SelW in primary cultured cells derived from embryonic cerebral cortex was knocked down with
small interfering RNAs (siRNAs), SelW siRNA-transfected neuronal cells were more sensitive to the oxidative stress induced
by treatment of H2O2 than control cells. TUNEL assays revealed that H2O2-induced apoptotic cell death occurred at a higher frequency in the siRNA-transfected cells than in the control cells. Taken
together, our findings suggest that SelW plays an important role in protection of neurons from oxidative stress during neuronal
development. 相似文献
997.
998.
Shweta R. Urva Beom Soo Shin Victor C. Yang Joseph P. Balthasar 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2009,877(8-9):837-841
A sensitive high performance liquid chromatography method (HPLC) has been developed for the quantification of doxorubicin in mouse plasma and tissues. Samples of serum or tissue homogenates, 20 μl, were analyzed following a single step protein precipitation using perchloric acid (35%, v/v). Doxorubicin was separated from the internal standard, daunorubicin, on a Zorbax 300SB C18 column at 35 °C. Mobile phase was comprised of acetonitrile and water (25:75) containing 0.1% triethylamine, and was adjusted to pH 3 with phosphoric acid. Peaks eluting from the column were detected with a fluorescence detector with excitation and emission wavelengths of 480 and 560 nm, respectively. Standard curves were linear in the range 5–1000 ng/ml, and correlation coefficients were typically greater than 0.999. Intra-assay recoveries ranged from 94.7 to 99.9%, and inter-assay recoveries were in the range of 95.2–101%. The associated coefficient of variation (CV) was less than 10% in all cases. The method was successfully applied to investigate doxorubicin plasma pharmacokinetics and tissue distribution in athymic Foxnu mice. 相似文献
999.
Five plant leaf extracts (Pine, Persimmon, Ginkgo, Magnolia and Platanus) were used and compared for their extracellular synthesis
of metallic silver nanoparticles. Stable silver nanoparticles were formed by treating aqueous solution of AgNO3 with the plant leaf extracts as reducing agent of Ag+ to Ag0. UV-visible spectroscopy was used to monitor the quantitative formation of silver nanoparticles. Magnolia leaf broth was
the best reducing agent in terms of synthesis rate and conversion to silver nanoparticles. Only 11 min was required for more
than 90% conversion at the reaction temperature of 95 °C using Magnolia leaf broth. The synthesized silver nanoparticles were
characterized with inductively coupled plasma spectrometry (ICP), energy dispersive X-ray spectroscopy (EDS), scanning electron
microscopy (SEM), transmission electron microscopy (TEM), and particle analyzer. The average particle size ranged from 15
to 500 nm. The particle size could be controlled by changing the reaction temperature, leaf broth concentration and AgNO3 concentration. This environmentally friendly method of biological silver nanoparticles production provides rates of synthesis
faster or comparable to those of chemical methods and can potentially be used in various human contacting areas such as cosmetics,
foods and medical applications. 相似文献
1000.
Byoung Chan Kim Daniel Lopez‐Ferrer Sang‐Mok Lee Hye‐Kyung Ahn Sujith Nair Seong H. Kim Beom Soo Kim Konstantinos Petritis David G. Camp Jay W. Grate Richard D. Smith Yoon‐Mo Koo Man Bock Gu Professor Jungbae Kim Professor 《Proteomics》2009,9(7):1893-1900
A stable and robust trypsin‐based biocatalytic system was developed and demonstrated for proteomic applications. The system utilizes polymer nanofibers coated with trypsin aggregates for immobilized protease digestions. After covalently attaching an initial layer of trypsin to the polymer nanofibers, highly concentrated trypsin molecules are crosslinked to the layered trypsin by way of a glutaraldehyde treatment. This process produced a 300‐fold increase in trypsin activity compared with a conventional method for covalent trypsin immobilization, and proved to be robust in that it still maintained a high level of activity after a year of repeated recycling. This highly stable form of immobilized trypsin was resistant to autolysis, enabling repeated digestions of BSA over 40 days and successful peptide identification by LC‐MS/MS. This active and stable form of immobilized trypsin was successfully employed in the digestion of yeast proteome extract with high reproducibility and within shorter time than conventional protein digestion using solution phase trypsin. Finally, the immobilized trypsin was resistant to proteolysis when exposed to other enzymes (i.e., chymotrypsin), which makes it suitable for use in “real‐world” proteomic applications. Overall, the biocatalytic nanofibers with trypsin aggregate coatings proved to be an effective approach for repeated and automated protein digestion in proteomic analyses. 相似文献